Refrigerators are home appliances that store foods in a refrigerated or frozen state. An ice making device for making ice is commonly mounted to such a refrigerator. When the ice making device is included in a refrigerator, a water supply mechanism for making ice is provided. Here, an important factor is accurately controlling an amount of water to be supplied for making ice. In particular, in an ice making device for making globular or spherical ice pieces, an amount of supplied water should be accurately controlled. For example, if the amount of supplied water is insufficient, the ice pieces will not be globular or spherical. On the other hand, if an amount of supplied water is excessive, an ice making tray may be broken due to the volume expansion of ice during the ice making process.
FIG. 1 illustrates an example prior art water supply system for making ice in a refrigerator.
Referring to FIG. 1, a water supply passage is connected to a water supply source 1, and a switching valve 2 is mounted on the water supply passage. A flow sensor 3 is mounted on an outlet side of the switching valve 2, and the water supply passage has an end connected to a water supply hole of an ice maker 5. The flow sensor 3 and the valve 2 are electrically controllably connected to a controller 4 (e.g., a Micom).
In some examples, a flowmeter may be used as the flow sensor 3, and an amount of water to be supplied may be calculated according to the number of pulses of the flowmeter corresponding to the rotation number of the flowmeter. When the water is completely supplied, a valve locking signal may be output from the controller 4 to close the valve 2.
A method of supplying water for a time preset in the controller 4 is another method of supplying water into the ice maker. For example, if a water supply time is set to about five seconds, water may be unconditionally supplied for about five seconds regardless of a water-pressure of a water supply source.
In the case of time control, since it is impossible to consider a water supply deviation due to the pressure, an amount of water supplied into an ice making tray may be significantly different depending on the pressure of water to be supplied.
In the case of flow sensor control, when the flow sensor is used in a low water-pressure area, water may be excessively supplied more than a target amount. This may occur because an impeller of the flow sensor may not operate due to the low water pressure, and thus water may pass around the impeller to increase an amount of supplied water to the detected pulse value.
FIG. 2 illustrates an excessive water supply phenomenon occurring when water supply is controlled using the flow sensor in the low water-pressure area.
As shown in FIG. 2, more than the target amount A of water is supplied in the low water-pressure area.